調試要求：

1.MCU:AT89S52芯片或AT89C52

2.晶振:12MHz

調試注意：

本程序不帶溫度補償

1.LCD1602液晶屏有顯示後，才接入超聲波模塊。

2.注意超聲波模塊電源的極性。不清楚請參好淘寶的電路圖

3.沒有選用頻率為12MHz晶振，用了別的頻率晶振,單片機定時器的測量值與發出的40KHz頻率脈衝不對。

4.使用者經常誤發出20KHZ脈衝當40KHZ脈衝。（40KHz頻率脈衝，週期25us,占空比為50 = 12.5us）

5.如果是用開發板調超聲波模塊,請檢查開發板上的電路是否與超聲波模塊的

控制腳復用了, 若復用了,請通過跳線分開發板上的電路。

6.如果使用的是萬用板，請確定單片機的復位電路和晶振電路是否正常，同時單片機的31腳（EA）記得

接高電平。-The debugging requirements: 1.MCU: AT89S52 chip AT89C52 2. Crystal: 12MHz debugging Note: the program without the temperature compensation 1.LCD1602 LCD display access ultrasonic module. Note ultrasonic module power supply polarity. Unclear please refer to the a good Taobao circuit diagram 3. Chosen frequency 12MHz crystal oscillator with a different frequency crystal, the microcontroller timer measurement values ​ ​ with the issue 40KHz frequency pulse is not right. Users often mistakenly issued 20KHZ pulse when 40KHZ pulse. (40KHz frequency pulse, cycle 25us, a duty cycle of 50　= 12.5us), 5. Tune with development board ultrasonic module, please check the development board circuit with the the ultrasonic module control pin multiplexing, Ruofu by jumper division developed the circuit board. 6 If you are using a wildcard board, to determine whether the microcontroller reset circuit and crystal oscillator circuit, microcontroller 31 feet (EA) remember to connect the high level